1. Field
This invention relates generally to modular articulated guide assemblies, and is concerned in particular with although not limited in use to feed chutes adapted to convey belted machinegun ammunition.
2. Description of Related Art
Soldiers engaged in combat must be able to operate belt-fed guns with a high degree of reliability. As belted machinegun ammunition is pulled from its storage container by the weapon's firing cycle, the belt can swing, sag, twist, and/or snag, thus causing the weapon to jam. Feed chutes minimize these tendencies by supporting and guiding the ammunition belt.
There are three basic types of known ammunition feed chutes: A) Formed Sheet-metal, B) Nested Injection-molded Links with Wire-tensioned Interlocks, and C) Rigid. Guiding Frames.
Type A designs use stamped metal pieces that are formed into C-shaped lugs that are linked together by means of sliding, semi-flexible tabs. Type B designs use injection molded C-shaped lugs that are nested and held in contact with tensioning cables. Type C designs utilize a series of ridged frames that are connected by essentially ridged bridging structures.
Type B and Type C feed chutes are only suitable for use with weapons that are mounted in fixed positions relative to their ammunition sources.
Type A feed chutes offer the ability to extend and retract while flexing in multiple directions, thus making them useful for man-portable weapons. However, they gain this capability by making serious compromises. For example:                They are expensive to manufacture.        They are heavy.        They are vulnerable to impact damage.        The segments between the articulating joints are necessarily flat, requiring special low-friction surface treatments to promote the movement of the ammunition belt across the interior surfaces of the chute.        When damaged, they are difficult to repair in the field because specialized tooling and fixtures are necessary.        It is difficult to assemble/disassemble segments into preferred lengths because specialized tooling and fixtures are necessary.        The overlapping plate edges present on their interior surfaces create a snagging hazard, particularly when the chute is flexed in any direction.        